Breakthrough could cut data network energy consumption

German researchers have developed a new technique that promises to help reduce the energy consumed by data transfer over optical networks.

The University of Stuttgart's Institute of Electrical and Optical Communications Engineering and the Institut für Mikroelektronik Stuttgart have set a new world record for energy efficiency in integrated silicon.

Using a newly developed backside metal mirror, the researchers achieved coupling efficiency of 87% between optical fibres and photonic integrated waveguides on silicon wafers.

Current optical senders and receivers are based on expensive indium phosphide substrates.

As silicon is transparent at the used light frequency, it can be used for waveguiding structures. But this requires light to be efficiently guided in silicon waveguides and coupled from one component to another. This process inevitably results in energy losses.

But the record 87% efficiency achieved by the researchers could help keep these losses low, paving the way for more efficient integration of optical senders and receivers in silicon.

With global internet traffic growing exponentially, the ICT sector is under intense pressure to improve the energy efficiency of telecom networks. Increasing global adoption of residential fibre will only compound the problem.